Gigapan Comments
(2)

Whether a xenolith gets cooked (metamorphosed) or
not depends on a number of factors. It's
certainly common for many xenoliths (but not all)
to have at least a little contact metamorphism at
their margins and some are pervasively
metamorphosed. I don't recall seeing any
evidence of metamorphism in this particular
xenolith, but I didn't linger and examine it
as much as I would have liked to.